diff --git a/docs/clang_tidy.md b/docs/clang_tidy.md
index fcf2184..cd5d1cc9 100644
--- a/docs/clang_tidy.md
+++ b/docs/clang_tidy.md
@@ -28,7 +28,7 @@
 
 Instead of building with `"Unix Makefiles"`, generate build files for Ninja with
 ```
-cmake -GNinja ../llvm
+cmake -GNinja -DCMAKE_BUILD_TYPE=Release ../llvm
 ```
 
 Then, instead of using `make`, use ninja to build the clang-tidy binary with